SP0256 (Sanofi)

SP0256 is an investigational mRNA-based vaccine candidate developed by Sanofi Pasteur for the prevention of Respiratory Syncytial Virus (RSV) infection. Developed using mRNA technology originally from Translate Bio (which Sanofi acquired in 2021), the vaccine delivers messenger RNA encapsulated in lipid nanoparticles (LNPs) to host cells. These cells then translate the mRNA into the RSV fusion (F) protein, a critical surface protein the virus uses to enter human cells. The expressed protein acts as an antigen, stimulating the host's immune system to produce neutralizing antibodies and activate cellular immune responses to provide protection against future RSV exposure. SP0256 has been evaluated in Phase I/IIa clinical trials (NCT04752111) to assess its safety and immunogenicity in healthy adults, including those aged 60 and older, who are at high risk for severe RSV disease.

Other names

Sanofi RSV mRNA vaccineRSV mRNA vaccine